Washington, D.C. — To account for changes in population, the principle of “one person, one vote” requires states to redraw their election districts every 10 years. In some states, legislators can manipulate district boundaries to benefit their own political party, engaging in extreme partisan gerrymandering. Tomorrow, the U.S. Supreme Court will hear arguments in Gill v. Whitford, a case in which a group of voters—represented by the Campaign Legal Center—are challenging maps drawn in Wisconsin. The case will determine whether these maps were drawn unconstitutionally to benefit one political party over another.

While Wisconsin is currently at the center of this fight, it is just one of several states where partisan gerrymandering is particularly acute. Extreme partisan gerrymandering weakens voters’ ability to affect election outcomes and exercise accountability over government, negatively affecting the responsiveness of legislators and crippling fair representation. Ahead of tomorrow’s hearing, Center for American Progress experts Liz Kennedy and Billy Corriher have prepared state-specific fact sheets on states with some of the most extreme examples of partisan gerrymandering and its consequences: Wisconsin, Michigan, North Carolina, Ohio, Rhode Island, and Virginia.

“Gerrymandering leads to less competitive elections, and this means legislators don’t have to worry about what voters think. Democracy is about voters being able to influence their elected officials, but gerrymandering makes it harder for voters to make their voice heard,” said Billy Corriher, deputy director of Legal Progress at the Center for American Progress and co-author of the fact sheets.

In the 2012 and 2014 elections, Republican candidates for the Michigan House of Representatives lost the total statewide vote but picked up several more seats than Democrats. This gerrymandered Republican majority has defied the will of Michigan voters, with severe impacts on public health, economic equity, and civil rights. In 2012, voters overturned a law that allowed the state to take over local governments that it decided faced a fiscal emergency, but the Legislature passed a new version of the law. Gov. Rick Snyder (R) appointed emergency managers to take over the local government of Flint, Michigan. In 2014, these managers switched the source of the city’s water, leading to an outbreak of Legionnaires’ disease and toxic levels of lead poisoning in children throughout the city. In addition, the Legislature did not approve a bill that would have given voters the chance to replace the state’s flat income tax with a progressive tax that would reduce rates for lower-income taxpayers and raise rates on the wealthy—a move supported by two-thirds of voters, according to a 2015 poll. The state is moving backwards on civil rights. A 2013 poll found that the vast majority of Michiganders support adoption rights for same-sex couples, and more than 75 percent support laws banning discrimination against LGBT people. However, in 2015, the state Legislature passed a law that allows adoption agencies to discriminate against same-sex couples in the name of religious freedom.

“The bottom line is that extreme partisan gerrymandering discriminates against targeted voters by locking them out of achieving representational power. This prevents progress on solutions that majorities of voters support, such as a higher minimum wage and expanded Medicaid programs,” said Liz Kennedy, director of Democracy and Government Reform at the Center for American Progress and co-author of the fact sheets. “In Gill v. Whitford, the Supreme Court has to stand up for the right to fair representation in our democracy and set limits on partisan gerrymandering to prevent these continuing abuses.”